tour: change color on links to make them visible

Fixes golang/go#13121

Change-Id: Id8bad9392fd78c6c816b4e6454269055881442f1
Reviewed-on: https://go-review.googlesource.com/17405
Reviewed-by: Minux Ma <minux@golang.org>
diff --git a/static/css/app.css b/static/css/app.css
index 123a30f..ef74c36 100755
--- a/static/css/app.css
+++ b/static/css/app.css
@@ -16,9 +16,12 @@
     outline: none;
 }
 a {
-    color: inherit;
+    color: #375eab;
     text-decoration: none;
 }
+a.logo, .toc a {
+    color: inherit;
+}
 h1, h2, h3, h4 {
     color: #333;
     line-height: 32px;
@@ -202,10 +205,6 @@
 .menu-button[syntax-checkbox].active:after {
     content: ' on';
 }
-#right-side a {
-    color: #375eab;
-    text-decoration: none;
-}
 #file-menu .menu-button {
     float: right;
 }